Fluid-treating apparatus



Dec. 19, 1944. w; M. PRATT FLUID-TREATING APPARATUS Filed June 23, 1942 T NM m M 0 w w E w BYE U A TTORNE if Patented Dec. 19, 1944 UNITED STATES} PATENT OFFICE 2,365,492 FLUID-TREATING APPARATUS Wentworth M. Pratt, Los Angeles, Calif.

Application June 23, 1942, Serial No. 448,100

1 Claim.

This application relates to apparatus used in the treatment of fluids, such as water filters and water softeners, and has for an object the provision of a new and simplified type of construction of apparatus of this general nature.

It is common practice to purify water by passing it through a bed of treating material confined within a suitable vessel, for which purpose inlet and outlet conduits are connected with the vessel at appropriate, spaced locations. It is also customary to interpose a suitable screen between the bed of treating material and each of the conduits, so as to prevent escape of the material from the vessel. However, in the production of small sized apparatus of this general nature, such as that intended for domestic use, the problem of design and installation of such screens is often complicated by consideration of speed and economy of assembly, particularly when being installed permanently. A further object of my present invention, therefore, is to provide a simplified permanent mounting for the screens whose function it is to retain the fluid-treating material of apparatus of the character indicated.

A more detailed object in this connection is to provide a screen mounting as described, which makes possible the positioning of the screen with a minimum expenditure of time and effort, and yet assure ample rigidity of the mounting to anchor it permanently in position.

A still further object is the provision of a screen mounting as described, which does not rely upon screws, rivets, or other fastening devices whichmust extend through the wall of the vessel in which the screens are mounted, with the result that the screen mounting of my invention has no detrimental eifect upon the ornamental appearance of the exterior of the apparatus, nor does it require any protruding elements such as screw or rivet heads, or other interruption in the smooth exterior of the apparatus, which might otherwise interfere with its being kept in a clean and sanitary condition.

The invention possesses other objects and valuable features, some of which, with those enumerated, will be set forth in the following description of the preferred embodiment of the invention illustrated in the drawing accompanying and forming part of the specification. It is to be understoodthat I do not limit myself to the showing made by the said drawing and description as I may adopt variations of the preferred form within the scope of my invention as defined in the claim. 1

Referring to the drawing:

Figure 1 is a vertical, medial sectional view of a portable water softener wherein the watersoftening material is retained by a screen mounted in accordance with the principles of the present invention.

Figure 2 is a horizontal, transverse sectional view, the plane of section being indicated by the line 2-2 of Figure l and the direction of view by the arrows.

Figure 3 is a transverse, horizontal sectional view, the plane of section being indicated by the line 3-3 of- Figure 1 and the direction of view by the arrows.

The drawing illustrates the present invention embodied as one of the details of construction of a portable water softener intended for domestic use. The principle upon which this type of fluidtreating apparatus operates is that of passing the water to be softened through a body of granular mineral material, and toward this end the apparatus illustrated comprises a vessel 6, preferably of cylindrical form, and having its upper end closed by a head I integral with the body of the vessel and having a central aperture 8 threaded to receive a discharge tube 9 a bore of which leads from the interior of the vessel 6. The lower end of the vessel 6 is provided with a peripheral flange ll against which a bottom head I2 is removably clamped as by a plurality of screws I3,

the heads of which are exposed at the under surface of the lower head l2 with the result that they are entirely concealed from view when the device is standing erect as in its operated position. As a further contribution toward the ornamental appearance of the apparatus, and in order to protect the structure upon which it stands, I prefer to provide a rubber sheath l4 enclosing the flange H and the outer edge It of the lower head l2.

The lower head I2 is also provided with a central opening l1. leading to the interior of the vessel 6. However, in this instance communica tion is established with a lateral passage 18 through the outer end of which a rubber tube I9 communicates so as to provide convenient means for connecting the apparatus to a source of supply of water to be softened, such as an ordinary domestic water faucet 2|.

The vessel 6 serves as a reservoir adapted to contain a suitable supply of water-softening mineral 26 preferably in granular form of such size that when water is caused to flow upward through the vessel 6 it percolates through the mass of material, i. e., around the granular particles thereof at sufficiently slow rate to insure its being adequately treated before the water passes out of the upper opening 8 and hence through the delivery tube.

In order to retain the granules of water softening material 26 within the vessel 6, i. e., against all possibility of its escape from the vessel through either of the tubes 9 or I 9, I have provided upper and lower screens 21 and 28 respectively interposed between the material 26 and the upper tube 9 and the lower tube l9, respectively. Each.

of these screens 21 and 28, is preferably in the form of a fiat disc 29 of suitable foraminous material, preferably sheet brass, having a peripheral upstanding flange 3!, the outside diameter of which is so proportioned that it establishes a driving fit with the interior of the vessel 6.. That is to say, each of the screens is so proportioned with respect to the interior of the vessel 6 that it can be forced into the vessel where it will be anchored so firmly that it will be retained in position without any additional means for there anchoring it.

A forced fit of the type which I find it desirable to use in conjunction with the apparatus of the present invention is defined as one having an average metal interference of 0.0005 d and requiring considerable pressure in assembling. (Websters New International Dictionary, second edition, unabridged, 1940). Ordinarily, machine partsareformed to provide afit of this nature by an actual machining process wherein the two parts to beinterfitted are turned and cut in such relative time that the part which is to be slipped inside of the other is of slightly greaterdiameter than the part which is to contain it. Obviously,

this requires great precision of manufacture, each part having to be turned on a lathe or the like andthus requirin the .services of a skilled artisan. The present invention, on the other hand, contemplates forming this forced fit, or driving fit as it is sometimes called, by means of a much less expensive process without detracting from its reliability. Instead of depending upon accurate machining of the inside diameter of the vessel 6 in proportion to the outside diameter of the peripherial flanges 3| of the screens 2'! and 28, I have provided other means for establishing the metal interference required for a forced fit of this nature. Accordingliuthe parts are susceptible of manufacture by a relatively inexpensive die stamping process which of course reduces the cost of manufacture to a very considerable degree.

A plurality, preferably two, of longitudinally extendin beads 36 are formed on the interior of the vessel 6. The parts are so proportioned and arranged that the dedendum circle (i. e., the diameter of a circle just touching the crest of these beads 36) is materially less than the outside diameter of the flanges 3i. Accordingly, when the screens 2? and 28 are 'pressed'into' the vessel 6. the 'projecting'beads 36 actually lie within the path of portions of the screens with the result that these beads provide the metal interference required for a forced fit of the nature desired in the construction. Accordingly, after assembly of the device an indentation 31 will have been formed in the outer peripheral edge of each of the screens 2'! and 28, in registry with each of the beads 36; and the beads 36 will press so strongly against the metal defining these indentations 31 that the screens will positively be retained in the position to which they are pressed.

Another detail of construction to which attention should be directed lies in the relationship between the shape of each head 1, l2, and the screen 21, 28 associated therewith. Each of these screens, it will be observed, is flat, whereas the head associated therewith is bowed outwardly, with the re ult that a material space 4| remains between the upper head 'I and the screen 21 associated therewith, and a similar space 42 is left between the lower head l2 and the screen 28 associated therewith. The function of these spaces 4! and 42 is similar to that of a manifold in that it assures flow throughout the entire area of each of the screens 2'! and 28. For example, in the case of the lower head l2, water entering the receptacle 6 by way of the central opening I! is permitted to fiow at even pressure to all of the area of the screen 28, thus avoiding the localized fiow which is a common fault in apparatus of this general type and which results in uneven distribution of the water being treated throughout the area of the treating material contained 7 area of the vessel 6 ate uniform rate. Concentration of flow is therefore completely eliminated" and, on the contrary, the evenflow, so desired in connection with apparatus of this type, is assured, The space 4| at the top of the apparatus functions similarly inasmuch as it permits Waterto leave the treating material 26 throughout the entire area of the upper screen 21 and hence by way of the manifold space 4!, to leave the vessel 6 by Way of the central opening 8 without however promoting any concentration of flow in that portion of the vessel where the treating material 26 is confined.

I claim:

Fluid treating apparatus, comprising a straight-sided cylindrical vessel, a head closing each end thereof, means for connecting a conduit to each of said heads in communication with the interior of said vessel, means associated with each of said heads for confining fluid-treating material within said vessel, said confining means being spaced from said heads and thereby providing manifold spaces with which said conduits communicate, each of said confining means comprising a disc of foraminous material and an upstanding peripheral flange thereon, and means establishing a force fit between said discs and said vessel comprising a plurality of beads on the interior surface of said vessel and projectin inwards therefrom to an addendum circleof less diameter than that of said 'discs whereby-said flanges are deformed when said discs are pressed into position within said vessel.

WENTWORTH M. PRATT. 

